"Non-herbivore" is a very generic term, it also includes mycophagous insects, saprophagous, and so on. But I think your question refers principally to the carnivorous insects and particularly to zoophagous insects on other insects (= entomophagous insects), which comprise predators and parasitoids. Even among entomophagous insects, there are various degrees of magnitude of the food spectrum, according to different species; therefore there are polyphagous, oligophagous, monophagous insects even among them ... if you want, you can search and find many examples. The first one which comes to mind is suggested by the cases of biological control interventions against insect pests accidentally introduced in new countries, by using their specific antagonists (often parasitoids) specifically collected in the country of origin of the pest, and secondarily introduced in order to take advantage of the activity of these beneficial insects in the same new countries. One example of monophagous parasitoid: Encarsia berlesei, useful against the scale Pseudaulacaspis pentagona.

Regards,

Rinaldo Nicoli

This is very commonly the case with parasitoid wasps. Less common in actual predators, but I am sure a sizeable list of cases could be compiled for those too. It's also a matter of the level of specificity you expect. For example, there may be tens or hundreds of ground beetle species that only eat snails. Based on shell shape or even on size alone, some may choose snails from one family only. Based on the availability of suitable snails in the area where the beetles live, that could happen to be only one snail species, but I guess that would be highly unusual.

A lot of species of Hymenoptera have very specific prey (Ammophila, Spheciformes a.s.o.), but the prey is usually for breeding and not for feeding of themselves.

I do not know, if your question aims also to these aspects.

Best, Rudolf Ritt

"Non-herbivore" is a very generic term, it also includes mycophagous insects, saprophagous, and so on. But I think your question refers principally to the carnivorous insects and particularly to zoophagous insects on other insects (= entomophagous insects), which comprise predators and parasitoids. Even among entomophagous insects, there are various degrees of magnitude of the food spectrum, according to different species; therefore there are polyphagous, oligophagous, monophagous insects even among them ... if you want, you can search and find many examples. The first one which comes to mind is suggested by the cases of biological control interventions against insect pests accidentally introduced in new countries, by using their specific antagonists (often parasitoids) specifically collected in the country of origin of the pest, and secondarily introduced in order to take advantage of the activity of these beneficial insects in the same new countries. One example of monophagous parasitoid: Encarsia berlesei, useful against the scale Pseudaulacaspis pentagona.

Regards,

Rinaldo Nicoli

Some species show this kind of specificity. For example, the genus Cerceris (Hymenoptera, Crabronidae) is known to feed on beetles. I've read that some species of this genus use to feed on specific beetle families.

For more info, see Looney et al. (2014), Sampling Buprestidae (Coleoptera) in Washington state with Cerceris californica Cresson (Hymenoptera, Crabronidae).

More, in   Crabronidae one "individuals"  prefer    weevils, but another (the same species!) -  prefer jewel beetles or another group of weevils.  The roots of such differences  are unknown.  It would be interesting to explore this phenomenon.

The fact is well-known (and well described) by the Coleoptera family of Coccinellidae, where both adults and larvae of some species feed on one or a short list of prey species.This specificity is used in agriculture to control pests : Rodolia cardinalis as predator of Icerya purchasi, Serangium parcesetosum against Dialeurodes citri...

The same is known in natura : Myzia oblongoguttata mainly feeding on Cinara pinea (and other Cinara sp.)...

Other species are polyphagous, on aphids, coccids, Aleyrodoidea, Psyllidae, Chrysomelidae... sometimes mainly on one vegetal species ! : Pullus ater on Quercus, Scymnus abietis on Pinus...

The reason for the specialisation of some Hymenoptera (as numbered above) is, that they have to bemuse their pray in order to keeping it fresh for breeding.

Not to kill but to bemuse it is a very difficult, and a very specific skill, because the topography of the nerves is very different in the species.

For example, a spider can be bemused with a unique sting in the central prosoma from ventral (and you have to beware from the chelizeres :) ), a caterpillar needs a sting in each segment of the body.

So the different species have a very specific pattern of prey. I do not know examples for specialisation on one species, but there are a lot with specialisation to one Genus or one Family, except one: Philanthus triangulum. Its prey is Apis mellifera.

Other examples:

Sphex funerarius: Ensifera

Corytes laticinctus: Cicades

Cerceris rybyensis: Halictus, Lasioglossum

Bembix rostrata: flies

Cerceris interrupta: Curculionidae

Sceliphron curvatum: spiders

A lot about this you can find in a classic book about insect behaviour:

Jean-Henry Fabre: Souvenirs Entomologiques

Best wishes Rudolf Ritt

Another beautiful example : the (not really, but...) one-to-one relation between the largest european Hymenoptera and (one of) the largest european Coleoptera : Megascolia  maculata and Oryctes nasicornis.

And what about ectoparasitism ? : Platypsyllus castoris (Coleoptera) and Castor fiber (Mammalia), Ctenophthalmus bisoctodentatus (Siphonaptera) and Talpa europaea (Mammalia), Braula caeca (Diptera) and Apis mellifera (Hymenoptera), Stenepteryx hirundinis (Diptera) and some (few) birds species (Avia)...

See

Some considerations about the ecology of Triatominae

Anais da Academia Brasileira de Ciências (2005) 77(3): 431-436

(Annals of the Brazilian Academy of Sciences)

ISSN 0001-3765

www.scielo.br/aabc

Not insects, but a family of spiders have a very species-specific prey: The Mastophoreae (bolas spiders) catch their prey by throwing  a short fiber with a sticky end at them. But this is is not the remarcable detail, remarcable is: they catch only the male of a particular moth spezies, which is attracted by the emission of the female pheromones of this species!

See more:

K. F. Haynes, C. Gemeno, K. V. Yeargan, J. G. Millarund K. M. Johnson (2002): Aggressive chemical mimicry of moth pheromones by a bolas spider. Chemoecology: 99-105

In the paper below you can find the answer to the hemiptera

Some considerations about the ecology of Triatominae

Anais da Academia Brasileira de Ciências (2005) 77(3): 431-436

(Annals of the Brazilian Academy of Sciences)

ISSN 0001-3765

www.scielo.br/aabc

Mr. Zhang, are you still here?

Sure.

Thanks for responses. Seems there are no general answers, and it depends on which group of entomophagous insects in discuss, right?

Hello Dear

Host specifity is one of tje most imprtant characteristic of an biological  control agentd including predator, parasitoid and pathogen. Application of polyphagus natural enemies of sgricultural pests can damaged to ecosystem by reduction the populations of helpful species and reduce biodiversity and environmental stability. Besy regards